Hello you can try this :

select * 
from my_table 
where Value_C in (
    select Value_C
    from my_table
    group by Value_C
    having count(Value_C) > 1 and max(Group_B)<> min(Group_B)
)  
and Value_D is not null 
order by Value_C;

Output

you can check this here : https://sqlfiddle.com/oracle/online-compiler?id=328fc9b1-3952-4fb8-b989-1acdddd1fcae